lifetantrik wrote:
OA is definitely wrong. Should be E.
you cannot write remainder(ND/NC) = remainder(D/C)
eg remainder(20/15) = 5, remainder(4/3) = 1
I agree. Let me expand this out to show the actual cases that prove insufficiency.
(1)
case 1: D = 19, C = 14. Obeys the statement, because when 20 is divided by 15, the remainder is 5. The answer to the question is also 5.
case 2: D = 28, C = 5. Obeys, the statement, because when 29 is divided by 6, the remainder is 5. The answer to the question, though, is 3. That's because when you divide 28 by 5, the remainder is 3.
(2)
case 1: D = 4, C = 3, N = 5. Obeys the statement, because when 20 + 15 is divided by 15, the remainder is 5. The answer to the question is 1.
case 2: D = 20, C = 15, N = 1. Obeys the statement, because when 20+15 is divided by 15, the remainder is 5. The answer to the question, however, is 5.
We have two different possible answers to the question for statement 1, and two different possible answers for statement 2. Now let's put them together.
(1+2)
case 1: D = 19, C = 14, N = 1.
- Obeys statement 1 (we already tested it).
- It also obeys statement 2, because when 19 + 14 is divided by 14, the remainder is 5.
- The answer to the question is 5.
case 2: D = 25, C = 6, N = 5.
- Obeys statement 1: 26 divided by 7 has a remainder of 5.
- Obeys statement 2: 125 divided by 30 has a remainder of 5.
- The answer to the question is 1.
So, the answer is (E).
That said, on the test, I would work on this one for about 90 seconds and then guess either C or E.
I believe that even without plugging numbers we can identify two equations from given statements using simply Dividend (N) = Divisor (D) * Quotient (Q) + Remainder (R)
Since there is no information about C nor N despite combination, the variables may or may not generate common values to consider, thus making insufficient to answer.